控制項不可見、未啟動或無法接受焦點，因此無法將焦點

can't move focus to the control because it is invisible

解決方法如下

function getFocusFunc(objId) {
    function doFocus() {
        if (document.getElementById) {
            document.getElementById(objId).focus();
        }
    }
    return doFocus;
}

function set_focus() {
    // Do whatever until you get to the point where you need to set focus to the iframe
    if(jQuery.browser.msie){
        setTimeout(getFocusFunc('objId'), 10);
    }else{
        $("#objId").focus();
    }
}